package main

import (
	"encoding/json"
	"fmt"
)

func main() {
	str := `{"data":"{\"data\":\"\",\"result\":0,\"belongType\":\"1\",\"bigAreaId\":1,\"cityId\":201,\"cityName\":\"北京\",\"companyType\":\"入门级买家\",\"currCredits\":0,\"currUCoins\":0,\"facePic\":\"http:\\\/\\\/img3.youxinpai.com\",\"fund\":160100.00,\"levelName\":\"\",\"sessionId\":\"99b4q1n3j1q91175244910271\",\"ticks\":\"2017-01-04 14:29:13\",\"userAddress\":\"地址地址\",\"userId\":15320,\"userKey\":\"99RFNMT1\",\"userName\":\"测试账户192\",\"userPhone\":\"16666666666\",\"vendorId\":11723,\"vendorName\":\"TEST-测试经销商192\"}","result":0}`
	var obj map[string]interface{}
	json.Unmarshal([]byte(str), &obj)
	switch t := obj["data"].(type) {
	case string:
		json.Unmarshal([]byte(t), &obj)
		fmt.Println("sessionId =", obj["sessionId"])
	}
}
